A frequency dip is caused by a single control area's disturbance, stabilizing at 59.85 Hz. How much load should be shed to restore frequency to 60 Hz?

To determine the amount of load that needs to be shed to restore frequency to 60 Hz from a frequency dip that stabilizes at 59.85 Hz, it’s important to understand the relationship between frequency and power balance in an electric power system.

When the frequency drops, it indicates that the generation is less than the load. In this instance, a frequency of 60 Hz represents the nominal operating frequency, while 59.85 Hz suggests that the system is operating underloaded or that additional generation is needed to rebalance the system.

Typically, the frequency of an electric power system decreases approximately linearly with a decrease in generation or an increase in load. Each 0.1 Hz drop is approximately associated with a certain percentage decline in system capacity, which can be roughly translated into a required load reduction in megawatts.

The amount of load shedding required can be determined using the formula that relates the frequency change to the amount of MW load that should be reduced. In this case, the difference in frequency from 60 Hz to 59.85 Hz is 0.15 Hz.

Thus, using the proportional relationship, it has been established through system studies that shedding approximately 500 MW of load can effectively raise the frequency back